Filter is used to filter the material of certain length, and the filter includes tensioning apparatus for being tensioned one section of filter between material and object, it is characterised in that, when the filter includes that conductive component is configured as contact, material keeps length by tensioning apparatus, whereinConductive component includes attachment portion external conductive connecting rod and filter. The present invention also relates to a kind of security system and its filter is made and used, as described herein.
